CFA Level II · CFA Level II Exam
Introduction to Commodities and Commodity Derivatives: formula sheet
Key formulas
- Commodity valuation basis
- Price = f(supply, demand, storage cost, convenience yield); no discounted cash flow
- Commodities have no cash flows, so equity and bond valuation methods do not apply directly.
- Futures price with carry costs (cost-of-carry idea)
- F₀ ≈ S₀ × (1 + r) + storage costs − convenience yield
- Higher storage cost pushes futures above spot; higher convenience yield pushes them down. Treat as a conceptual relationship unless the vignette gives a formula.
- Convenience yield effect
- Higher convenience yield → futures price lower relative to spot
- Strong near-term need for physical supply favours holders of the physical commodity.
- Futures gain or loss (long)
- Gain = (Settlement price − Previous settlement price) × Contract size × Number of contracts
- A short position has the opposite sign. Used for daily marking to market.
- Cash settlement amount
- Payment = (Final reference price − Contract price) × Quantity
- Positive means the long receives. Negative means the long pays.
- Fixed-for-floating swap payment
- Net payment to fixed payer = (Floating price − Fixed price) × Notional quantity
- Positive means the fixed payer receives. Only the net amount is paid.
- Margin rule
- Margin call if account balance < maintenance margin; restore to initial margin
- Check the vignette for whether the top-up is to initial or maintenance level.
- Cost-of-carry futures price (with convenience yield)
- F₀ = S₀ × (1 + r)^T + FV(storage costs) − FV(convenience yield)
- Conceptual form. Storage and interest raise F₀. Convenience yield lowers it. Use the exact form the vignette gives.
- Contango
- Longer-dated futures price > nearer-dated futures price
- Upward-sloping curve. Defined by shape only, not by expected price direction.
- Backwardation
- Longer-dated futures price < nearer-dated futures price
- Downward-sloping curve. Usually linked to high convenience yield.
- Net cost of carry condition
- Contango if r + storage > convenience yield; backwardation if convenience yield > r + storage
- Compare the two sides on the same time basis, such as annualised rates.
- Roll yield sign
- Backwardation: roll yield > 0 for a long position; contango: roll yield < 0
- Assumes the long rolls from the near contract to the next, with the spot price unchanged.
- Theory of storage (cost of carry with convenience yield)
- F₀ = S₀ × (1 + r + c − y)
- Rates form: r, c and y are rates for the same period (interest, storage cost, convenience yield). In money terms, the discrete form is F₀ = S₀ × (1 + r) + FV(storage costs) − FV(convenience yield). Do not mix the two forms. Continuous form: F₀ = S₀ × e^((r + c − y)T). Backwardation (F₀ < S₀) needs y > r + c.
- Insurance theory (normal backwardation)
- Futures price < Expected future spot price
- Hedgers are net short, speculators are net long and earn a positive risk premium.
- Hedging pressure: net short hedgers
- Futures price < Expected future spot price
- Speculators are long and earn a positive premium.
- Hedging pressure: net long hedgers
- Futures price > Expected future spot price
- Speculators are short. This is normal contango. The long side earns a negative premium.
- Convenience yield and inventory
- Low inventory → high convenience yield → backwardation if y > r + c; High inventory → low convenience yield → contango
- Convenience yield is a benefit of holding the physical commodity, not of holding the futures.
- Total return
- Total return = spot return + roll return + collateral return
- Approximation used in the curriculum. Returns are for the same period.
- Spot return
- Spot return = (S1 − S0) ÷ S0
- Based on the spot price, not the futures price.
- Roll return (per roll)
- Roll return = (near-term futures price − farther-term futures price) ÷ near-term futures price
- Positive in backwardation, negative in contango. Sign convention is for a long position.
- Roll return from total futures change
- Futures price return ≈ spot return + roll return
- The price change on the rolled futures position, excluding collateral.
- Collateral return
- Collateral return = interest rate on collateral × period fraction
- Scale an annual rate to the holding period.
- Commodity index return
- Total return = spot return + roll return + collateral return
- Futures-based indexes earn all three. Roll return is positive in backwardation and negative in contango.
- Production weighting (S&P GSCI)
- Weight ∝ world production quantity × futures price
- Energy ends up with the largest weight. Weights shift as prices change.
- BCOM weighting rule
- Weights based on liquidity and production, with caps on sector and single-commodity weights
- Caps limit concentration, giving a more diversified index than S&P GSCI.
- Equity-linked exposure
- Producer equity return ≠ commodity price return
- Equities add operating leverage, hedging and market beta, so tracking is loose.
Quick revision
- Commodities are real assets with no cash flows, so returns come from price changes and the futures structure.
- Contango: futures prices are above spot, and longer-dated futures are higher than shorter-dated ones.
- Backwardation: futures prices are below spot, and longer-dated futures are lower than shorter-dated ones.
- Rolling a long position in contango usually gives negative roll yield, since you buy the higher-priced contract later.
- Rolling a long position in backwardation usually gives positive roll yield.
- A high convenience yield pushes the curve toward backwardation; high storage costs push it toward contango.
- Total return on a fully collateralised futures position = spot return + roll yield + collateral return.
- Insurance theory (normal backwardation in the Keynes sense) implies futures prices are below expected future spot prices, because hedgers pay a premium to speculators, so long positions earn a risk premium. This is a statement about futures versus expected spot, which is distinct from the curve shape comparing futures with current spot.
- The theory of storage links the curve to inventory levels, storage costs and convenience yield.
- Index design choices, such as weights and roll rules, can change returns even when the same commodities are held.
- Investors can access commodities through futures, funds, ETFs, equities of producers or notes, each with different tracking risks.
- Read the contract months in the vignette carefully, because roll yield depends on which two contracts you compare.
Common mistakes
- Valuing a commodity using discounted cash flows. Fix: Remember commodities produce no cash flows. Think supply, demand and cost of carry.
- Treating all commodities as equally storable. Fix: Check storability by sector. Gold stores easily; electricity, natural gas and livestock do not.
- Saying futures have no credit risk at all. Fix: Say credit risk is greatly reduced through margin and daily settlement, not eliminated.
- Treating a forward as marked to market daily. Fix: Daily marking is a futures feature. A forward usually settles only at maturity.
- Saying contango means prices are expected to rise. Fix: Contango is only a shape. Theory says it reflects carry costs, and the curve does not predict spot prices by itself.
- Adding convenience yield to the futures price. Fix: Convenience yield is a benefit to holders of the physical, so it lowers the futures price relative to spot.
- Treating backwardation as the same thing in all three theories. Fix: Always ask what the futures price is being compared with. Expected spot relates to the risk premium theories. Spot price relates to the storage theory.
- Saying insurance theory allows a negative premium for the long side. Fix: Insurance theory assumes hedgers are net short, so the long speculator earns a positive premium. The possibility of a negative premium comes from hedging pressure.
- Getting the roll return sign wrong in contango. Fix: You sell the near contract and buy the far one. Paying more for the far contract is a cost, so roll return is negative.
- Dividing the roll difference by the far price. Fix: The curriculum measures roll return relative to the near-term price: (near − far) ÷ near.
Exam tips
- Read the vignette for storability, seasonality and cyclicality cues, as they usually point to the answer.
- Be ready to contrast commodities with equities and bonds in one line: no cash flows, supply and demand driven.
- Do not overstate diversification or inflation hedging; pick answers that say 'may' or 'can'.
- Link sector traits to futures curve behaviour, since later topics build on this.
- Do not spend long on a question; there is no penalty for a wrong answer, so always select an option.
- Read who the party is and why it trades before choosing hedger or speculator.
- Check the sign of every gain or loss, and whether the position is long or short.
- Expect questions contrasting futures with forwards on credit risk, liquidity and customisation.